Premium
Elucidation of a side reaction occurring during nitroxide‐mediated polymerization of cyclic ketene acetals by tandem mass spectrometric end‐group analysis of aliphatic polyesters
Author(s) -
Albergaria Pereira Bruna de Fátima,
Tardy Antoine,
Monnier Valérie,
Guillaneuf Yohann,
Gigmes Didier,
Charles Laurence
Publication year - 2015
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7397
Subject(s) - chemistry , polymerization , ketene , tandem mass spectrometry , electrospray ionization , mass spectrometry , polyester , fragmentation (computing) , nitroxide mediated radical polymerization , end group , radical polymerization , polymer , combinatorial chemistry , organic chemistry , chromatography , computer science , operating system
Rationale In order to prevent side reactions while developing new polymerization processes, their mechanism has to be understood and one first key insight is the structure of the end‐groups in polymeric by‐products. The synthetic method scrutinized here is the nitroxide‐mediated polymerization (NMP) of a cyclic ketene acetal, a promising alternative process to the production of polyesters. Methods Polymer end‐group characterization was performed by mass spectrometry (MS), combining elemental composition information derived from accurate mass data in the MS mode with fragmentation features recorded in the MS/MS mode. Electrospray was used as the ionization method to ensure the integrity of original chain terminations and a quadrupole time‐of‐flight (QTOF) instrument was employed for high‐resolution mass measurements in both MS and tandem mass spectrometry (MS/MS) modes. Results Occurrence of side reactions in the studied polymerization method, first evidenced by an unusual increase in dispersity with conversion, was confirmed in MS with the detection of two polymeric impurities in addition to the expected species. Fragmentation rules were first established for this new polyester family in order to derive useful structural information from MS/MS data. In addition to a usual NMP by‐product, the initiating group of the second polymeric impurities revealed the degradation of the nitroxide moiety. Conclusions Unambiguous MS/MS identification of end‐groups in by‐products sampled from the polymerization medium allowed an unusual side reaction to be identified during the NMP preparation of polyesters. On‐going optimization of the polymerization method aims at preventing this undesired process. Copyright © 2015 John Wiley & Sons, Ltd.